On September 15th, when Destiny: The Taken King launches a lot of things will be changing, and it won't just be the way you level or new item stats and skills — it will also be the Marks you earn. When the expansion launches all of your Vanguard and Crucible Marks will be replaced and converted.
Legendary Marks will replaced both Vanguard and Crucible Marks, these new Marks will be available account-wide — like Glimmer. The Legendary Marks will not be subject to weekly limits, but they will be limited to a specific amount at one time.
Your Guardian will only be able to hold 200 Legendary Marks at a time. Let's say you hit your limit, you can go spend your Legendary Marks , then go out and earn more until you hit your limit again. What can you spend Marks on? Legendary blueprints, exotics, Legendary Engrams and item upgrades.
Legendary Marks can be sourced from Weekly Heroic, Daily Heroic, Daily Crucible, and from Sharding Legendary Items will give you Legendary Items. You might be wondering what happens to existing Vanguard and Crucible Marks? They are converted into commendations.
Oh and in case you missed it, Bungie revealed the minimum level for The Taken King.